# Copyright (c) 2011 The Chromium Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.
"""GDB support for Chrome types.
Add this to your gdb by amending your ~/.gdbinit as follows:
python
import sys
sys.path.insert(0, "/path/to/tools/gdb/")
import gdb_chrome
end
This module relies on the WebKit gdb module already existing in
your Python path.
Use
(gdb) p /r any_variable
to print |any_variable| without using any printers.
"""
import datetime
import gdb
import gdb.printing
import webkit
# When debugging this module, set the below variable to True, and then use
# (gdb) python del sys.modules['gdb_chrome']
# (gdb) python import gdb_chrome
# to reload.
_DEBUGGING = False
pp_set = gdb.printing.RegexpCollectionPrettyPrinter("chromium")
def typed_ptr(ptr):
"""Prints a pointer along with its exact type.
By default, gdb would print just the address, which takes more
steps to interpret.
"""
# Returning this as a cast expression surrounded by parentheses
# makes it easier to cut+paste inside of gdb.
return '((%s)%s)' % (ptr.dynamic_type, ptr)
def yield_fields(val):
"""Use this in a printer's children() method to print an object's fields.
e.g.
def children():
for result in yield_fields(self.val):
yield result
"""
try:
fields = val.type.target().fields()
except:
fields = val.type.fields()
for field in fields:
if field.is_base_class:
yield (field.name, val.cast(gdb.lookup_type(field.name)))
else:
yield (field.name, val[field.name])
class Printer(object):
def __init__(self, val):
self.val = val
class StringPrinter(Printer):
def display_hint(self):
return 'string'
class String16Printer(StringPrinter):
def to_string(self):
return webkit.ustring_to_string(self.val['_M_dataplus']['_M_p'])
pp_set.add_printer(
'string16',
'^string16|std::basic_string<(unsigned short|base::char16).*>$',
String16Printer);
class GURLPrinter(StringPrinter):
def to_string(self):
return self.val['spec_']
pp_set.add_printer('GURL', '^GURL$', GURLPrinter)
class FilePathPrinter(StringPrinter):
def to_string(self):
return self.val['path_']['_M_dataplus']['_M_p']
pp_set.add_printer('FilePath', '^FilePath$', FilePathPrinter)
class SizePrinter(Printer):
def to_string(self):
return '%sx%s' % (self.val['width_'], self.val['height_'])
pp_set.add_printer('gfx::Size', '^gfx::(Size|SizeF|SizeBase<.*>)$', SizePrinter)
class PointPrinter(Printer):
def to_string(self):
return '%s,%s' % (self.val['x_'], self.val['y_'])
pp_set.add_printer('gfx::Point', '^gfx::(Point|PointF|PointBase<.*>)$',
PointPrinter)
class RectPrinter(Printer):
def to_string(self):
return '%s %s' % (self.val['origin_'], self.val['size_'])
pp_set.add_printer('gfx::Rect', '^gfx::(Rect|RectF|RectBase<.*>)$',
RectPrinter)
class SmartPtrPrinter(Printer):
def to_string(self):
return '%s%s' % (self.typename, typed_ptr(self.ptr()))
class ScopedRefPtrPrinter(SmartPtrPrinter):
typename = 'scoped_refptr'
def ptr(self):
return self.val['ptr_']
pp_set.add_printer('scoped_refptr', '^scoped_refptr<.*>$', ScopedRefPtrPrinter)
class LinkedPtrPrinter(SmartPtrPrinter):
typename = 'linked_ptr'
def ptr(self):
return self.val['value_']
pp_set.add_printer('linked_ptr', '^linked_ptr<.*>$', LinkedPtrPrinter)
class WeakPtrPrinter(SmartPtrPrinter):
typename = 'base::WeakPtr'
def ptr(self):
flag = ScopedRefPtrPrinter(self.val['ref_']['flag_']).ptr()
if flag and flag['is_valid_']:
return self.val['ptr_']
return gdb.Value(0).cast(self.val['ptr_'].type)
pp_set.add_printer('base::WeakPtr', '^base::WeakPtr<.*>$', WeakPtrPrinter)
class CallbackPrinter(Printer):
"""Callbacks provide no usable information so reduce the space they take."""
def to_string(self):
return '...'
pp_set.add_printer('base::Callback', '^base::Callback<.*>$', CallbackPrinter)
class LocationPrinter(Printer):
def to_string(self):
return '%s()@%s:%s' % (self.val['function_name_'].string(),
self.val['file_name_'].string(),
self.val['line_number_'])
pp_set.add_printer('tracked_objects::Location', '^tracked_objects::Location$',
LocationPrinter)
class PendingTaskPrinter(Printer):
def to_string(self):
return 'From %s' % (self.val['posted_from'],)
def children(self):
for result in yield_fields(self.val):
if result[0] not in ('task', 'posted_from'):
yield result
pp_set.add_printer('base::PendingTask', '^base::PendingTask$',
PendingTaskPrinter)
class LockPrinter(Printer):
def to_string(self):
try:
if self.val['owned_by_thread_']:
return 'Locked by thread %s' % self.val['owning_thread_id_']
else:
return 'Unlocked'
except gdb.error:
return 'Unknown state'
pp_set.add_printer('base::Lock', '^base::Lock$', LockPrinter)
class TimeDeltaPrinter(object):
def __init__(self, val):
self._timedelta = datetime.timedelta(microseconds=int(val['delta_']))
def timedelta(self):
return self._timedelta
def to_string(self):
return str(self._timedelta)
pp_set.add_printer('base::TimeDelta', '^base::TimeDelta$', TimeDeltaPrinter)
class TimeTicksPrinter(TimeDeltaPrinter):
def __init__(self, val):
self._timedelta = datetime.timedelta(microseconds=int(val['ticks_']))
pp_set.add_printer('base::TimeTicks', '^base::TimeTicks$', TimeTicksPrinter)
class TimePrinter(object):
def __init__(self, val):
timet_offset = gdb.parse_and_eval(
'base::Time::kTimeTToMicrosecondsOffset')
self._datetime = (datetime.datetime.fromtimestamp(0) +
datetime.timedelta(microseconds=
int(val['us_'] - timet_offset)))
def datetime(self):
return self._datetime
def to_string(self):
return str(self._datetime)
pp_set.add_printer('base::Time', '^base::Time$', TimePrinter)
class IpcMessagePrinter(Printer):
def header(self):
return self.val['header_'].cast(
gdb.lookup_type('IPC::Message::Header').pointer())
def to_string(self):
message_type = self.header()['type']
return '%s of kind %s line %s' % (
self.val.dynamic_type,
(message_type >> 16).cast(gdb.lookup_type('IPCMessageStart')),
message_type & 0xffff)
def children(self):
yield ('header_', self.header().dereference())
yield ('capacity_after_header_', self.val['capacity_after_header_'])
for field in self.val.type.fields():
if field.is_base_class:
continue
yield (field.name, self.val[field.name])
pp_set.add_printer('IPC::Message', '^IPC::Message$', IpcMessagePrinter)
class NotificationRegistrarPrinter(Printer):
def to_string(self):
try:
registrations = self.val['registered_']
vector_finish = registrations['_M_impl']['_M_finish']
vector_start = registrations['_M_impl']['_M_start']
if vector_start == vector_finish:
return 'Not watching notifications'
if vector_start.dereference().type.sizeof == 0:
# Incomplete type: b/8242773
return 'Watching some notifications'
return ('Watching %s notifications; '
'print %s->registered_ for details') % (
int(vector_finish - vector_start),
typed_ptr(self.val.address))
except gdb.error:
return 'NotificationRegistrar'
pp_set.add_printer('content::NotificationRegistrar',
'^content::NotificationRegistrar$',
NotificationRegistrarPrinter)
class SiteInstanceImplPrinter(object):
def __init__(self, val):
self.val = val.cast(val.dynamic_type)
def to_string(self):
return 'SiteInstanceImpl@%s for %s' % (
self.val.address, self.val['site_'])
def children(self):
yield ('id_', self.val['id_'])
yield ('has_site_', self.val['has_site_'])
if self.val['browsing_instance_']['ptr_']:
yield ('browsing_instance_', self.val['browsing_instance_']['ptr_'])
if self.val['process_']:
yield ('process_', typed_ptr(self.val['process_']))
if self.val['render_process_host_factory_']:
yield ('render_process_host_factory_',
self.val['render_process_host_factory_'])
pp_set.add_printer('content::SiteInstanceImpl', '^content::SiteInstanceImpl$',
SiteInstanceImplPrinter)
class RenderProcessHostImplPrinter(object):
def __init__(self, val):
self.val = val.cast(val.dynamic_type)
def to_string(self):
pid = ''
try:
child_process_launcher_ptr = (
self.val['child_process_launcher_']['impl_']['data_']['ptr'])
if child_process_launcher_ptr:
context = (child_process_launcher_ptr['context_']['ptr_'])
if context:
pid = ' PID %s' % str(context['process_']['process_'])
except gdb.error:
# The definition of the Context type may not be available.
# b/8242773
pass
return 'RenderProcessHostImpl@%s%s' % (self.val.address, pid)
def children(self):
yield ('id_', self.val['id_'])
yield ('listeners_',
self.val['listeners_']['data_'])
yield ('worker_ref_count_', self.val['worker_ref_count_'])
yield ('fast_shutdown_started_', self.val['fast_shutdown_started_'])
yield ('deleting_soon_', self.val['deleting_soon_'])
yield ('pending_views_', self.val['pending_views_'])
yield ('visible_widgets_', self.val['visible_widgets_'])
yield ('backgrounded_', self.val['backgrounded_'])
yield ('widget_helper_', self.val['widget_helper_'])
yield ('is_initialized_', self.val['is_initialized_'])
yield ('browser_context_', typed_ptr(self.val['browser_context_']))
yield ('sudden_termination_allowed_',
self.val['sudden_termination_allowed_'])
yield ('ignore_input_events_', self.val['ignore_input_events_'])
yield ('is_guest_', self.val['is_guest_'])
pp_set.add_printer('content::RenderProcessHostImpl',
'^content::RenderProcessHostImpl$',
RenderProcessHostImplPrinter)
gdb.printing.register_pretty_printer(gdb, pp_set, replace=_DEBUGGING)